Lubricant



Patented Apr. 6, 1943 LUBRICANT Frederick H. MacLaren, Munster, Ind.,assignor to Standard Oil Company, Chicago, Ill., a corporation ofIndiana No' Drawing. Application March 24, 1941,. Serial No. 384,946

26 Claims.

The present invention relates to a new composition of matter andparticularly to a new composition of matter capable of inhibiting thoxidation of lubricating oils, thereby materially decreasing thesusceptibility of such oils to form sludge, carbon and/or varnish-likedeposits and further possessing the property of depressing the pourpoint of the lubricating oil containing the same.

Straight petroleum lubricating oils are efiective within certain definedlimits of engine operating conditions but when these limits are exceededsuch oils frequently fail to give the desired performance demanded ofthem. Since, in modern engines designed to give increased performancethese limits are frequently exceeded, the use of straight mineral oilsas lubricants produce undesirable conditions within the engine. Thus,varnish and carbon formation are excessive and corrosion of improvedhard metal alloy bearings is frequently encountered.

In order to provide adequate year-round lubrication, it is frequentlythe practice to add to lubricating oils addition agents of various kindswhich possess the property of depressing the pour point of thelubricating oil. The addition of these pour point depressors inlubricating oils enables the oils to flow freely at relatively lowtemperatures so that proper lubrication may be attained at these lowtemperatures.

In order to obtain all of the foregoing desired properties in alubricating oil, it has been the general practice to add variousadditives to the oils, each additive imparting to the oil the specificproperty for which it is intended. Obvious y, such a procedure istime-consuming and uneconomical.

It is an object of the present invention to provide an improvedcomposition of matter possessing the property of depressing the pourpoint of lubricating oils and also the property of inhibiting theformation of slud e, carbon and/or varnish-like deposits in internalcombustion engines. particularly onand about the pistons and pistonrings thereof. It is a further object of the invention to provide animproved lubricating oil having a low pour point and which is notsusceptible to oxidation and the attendant formation of sludge, carbonor varnish-like deposits in internal com bustion engines, particularlyon and about the pistons and piston rings thereof.

Other objects and advantages of the present invention will becomeapparent as the description thereof proceeds.

I have discovered that a lubricating oil additive having the foregoingdesired properties may be obtained by reacting a condensation product ofan halogenated aliphatic hydrocarbon with an aromatic compound in thepresence of aluminum chloride, zinc chloride or other catalyst of theFriedel-Crafts type and subsequently reacting the condensation productwith a phosphorus sulfide, such as PzSz, P4S1o, P487, Pisa, or,preferably,

PzSs.

The halogenated aliphatic hydrocarbon is preferably a halogenatedlong-chain paraffin hydrocarbon having more than eight carbon atoms,such as parafiin'wax, petrolatum, ozocerite wax, etc. High viscosityparaffin oils, particularly heavy residual oil which has been treatedwith .chemicals or extracted with propane or other solvents for theremoval of asphalts, may be employed. The aromatic constituent in thepreparation of my starting material may be naphthalene, fluorene,phenanthrene, anthracene, coal tar residues and the like. Halogenatednaphthalene or other naphthenic or aromatic compounds equivalent tonaphthalene may be used as a condensation reagent in the reaction. Thepreparation of these condensation products is described in my UnitedStates Patents Nos. 1,963,917, 1,963,918, and others.

Other suitable modified condensation products having pour pointdepressing properties may be reacted with a phosphorus sulfide to obtainthe desired addition agent. An example of such modified condensationproduct is the product obtained by condensing an aromatic hydrocarbonwith a chlorinated aliphatic material of relatively high molecularweight such as a chlorinated parafiin wax and subsequently reacting theproduct thus obtained with an acylating agent and other compounds of thetype described in United States Patent 2,147,547.

The additive of the present invention is obtained by reacting acondensation product of the foregoing type with one of theaforementioned phosphorus sulfides, preferably P285 at a temperature offrom about 200 F. to about 500 F., preferably from about 300 F. to about400 F.,

preferably in a non-oxidizing atmosphere. From about 1% to about andpreferably fromabout 5% to about 25% of the phosphorus sulfide may beemployed. The product so obtained may then -with a basic reagent.

be purified by diluting the same with a diluent, such as hexane,settling, filtering and subsequently freeing the filtrate of the diluentby evaporation or distillation. If desired, any objectionable odor, ifpresent, may be eliminated by blowing the product with nitrogen or steamat elevated temperatures, preferably at 325 F. to 375 F.

The reaction product obtained by reacting a phosphorus sulfide with thecondensation product of a halogenated paraflin and an aromatichydrocarbon will be referred to hereinafter as the condensationproduct-phosphorus sulfide reaction product.

The condensation product-phosphorus sulfide reaction product may be usedas such or it may be further modified by forming a neutralized product.The condensation product-phosphorus sulfide reaction product normallyshows a titratable acidity which may be neutralized by treatment Thecondensation productphosphorus sulfide reaction product when neutralizedwith a basic reagent containing a metal constituent is characterized bythe presence or retention of the metal constituent of the reagent. Othermetal constituents such as a heavy metal constituent may be introducedinto the neutralized product by reacting the same with a salt of thedesired heavy metal.

The term neutralized condensation productphosphorus sulfide reactionproduct as used herein means a condensation product-phosphorus sulfidereaction product having at least about 1% of its titratable acidity,reduced by the reaction with a basic reagent, and includestheneutralized condensation product-phosphorus sulfide reaction productscontaining a metal constituent resulting from said neutralization orresulting from the reaction of a heavy metal salt with the condensationproduct-phosphorus sulfide reaction product treated with a basicreagent.

The neutralized condensation product-phosphorus sulfide reaction productmay be obtained by adding to the reaction product a suitable basiccompound such as a hydroxide, carbonate, or an oxide of an alkalineearth metal or an alkali metal, preferably potassium hydroxide or sodiumhydroxide. Other basic reagents may be used such as. for example,ammonia, or alkyl or aryl substituted ammonia. such as amines. Asaforesaid. when the condensation product-phosphorus sulfide reactionproduct is neutralized with a basic compound containing a metalconstituent the neutralized reaction product is characterized. by thepresence of a metal constituent of such basic reagent. Neutralizedreaction products containing a heavy metal constituent such as. forexample, tin, titanium. aluminum, chromium. cobalt, or iron and the likemay be obtained by reacting a salt of the desired heavy metal with thecondensation product-phosphorus sulfide reaction product which has beentreated with a basic reagent.

It will be understood that when the neutraliza tion is accomplished witha polyvalent basic material, such as dime. a product having excessbasicity may be obtained.

The preparation .of the additives of the present invention may beillustrated by the following examples which are given by way ofillustration and not intended to be a limitation on the scope of theinvention.

A condensation product having pour point depressing properties wasprepared by chlorinating asiaose a paramn wax having a melting point of"about 130 F. to a chlorine content of about 14% to about 15%. Thischlorinated paraflin wax was then mixed with about ten parts by weightof naphthalene and heated to a temperature of at least 130 F. About twoto three parts of aluminum chloride was then added to the hot mixtureand the mixture agitatedand maintained at the above said temperatureuntil the reaction was substantially completed. The condensation productwas then removed from the mixture, neutralized and the water-solublecompounds and loosely bound chlorine compounds removed therefrom.

The above condensation product was then mixed with 10% by weight ofphosphorus pentasulfide and the mixture agitated and maintained at atemperature of 240 F. to 315 F. for a period of three hours. Thereaction product was then taken up in hexane, filtered, and the filtratefreed of the solvent by evaporation. The final product contained 1.3%phosphorus and 2.03%

sulfur.

EXAMPLE II A portion of the reaction product of Example I before removalof the hexane, was treated with excess alcoholic KOH at a temperature ofF., and given several water washes to remove the excess KOH. The productwas then filtered, and freed of hexane by evaporation on a steam bath.The final product had a phosphorus content of 1.3%, a sulfur content of1.2% and a potassium content of 2.51%.

EXAMPLE III To the condensation product of Example I. was added 10% Passand the mixture heated at 380 F. for eight hours. The product was thendiluted with hexane, settled, filtered and the filtrate freed of thediluent by evaporation on a steam bath. The final product had a sulfurcontent of 1.54% and a phosphorus content of 1.28%.

EXAMPLE IV The reaction product of Example III was diluted in hexane andtreated with alcoholic'KOI-I in the manner described in Example II.

EXAMPLE V A portion of th product of Example IV was blown with steam ata temperature of 330 F. to 350 F. for four hours.

The effectiveness of the hereindescribed addition agents is demonstratedby the following engine test. The oils were first subjected to anaccelerated engine test made in a standard six cylinder automobile motoroperating for sixty hours at 35 B. H. P. and 3000 R. P. M. with an oilsump temperature of about 285 F. At the end of the test period theengine was dismantled and given a visual engine rating. In this visualrating a rating of 10 means that the engine had the appearance of theengine at the start of the test, while a rating of 1 means that theengine after the test was badly coated. Engines having appearancesbetween these extremes are given intermediate rating values. An engineafter being lubricated with a good conventional motor oil for a sixtyhour period is usually given a visual rating of about 5.

The following oils were subjected to the above test and the dataobtained tabulated in Table I. Oil A (control)A high grade SAE 20 motoroil.

Oil B--Oil A+0.25% condensation productphosphorus sulfide reactionproduct prepared as in Example V above.

Oil C-Oil A+0.'75% condensation productphosphorus sulfide reactionproduct prepared as in Example V above.

Oil DOil D+0.5% condensation productphosphorus sulfide reaction productprepared as in Example III, +05% of the reaction product prepared as inExample IV.

Table I Unricr- I head carbon I Ringbelt carbon Oil Overall In a secondtest about 250 cc. of the oil to be tested is heated at about 330 F.-332F. in a 500 cc. glass beaker in the presence of five square inches ofcopper and ten square inches of iron. Four glass rods of about sixmillimeter diameter are suspended in the oil which is stirred at about1300 R. P. M. with a glass stirrer having a 40" blade pitch. At statedintervals-oil samples are taken and sludge. acidity and viscosity valuesdetermined. The glass rods are also inspected for evidence of varnishformation thereon. Varnish values are based on the visual rating inwhich a glass rod free of any varnish is given a rating of 10, while abadly coated rod is given Rods having appearances between a rating of 1.these extremes are given intermediate values.

The following oils were subjected to the above test and the dataobtained are tabulated in Table II.

Oil EHigh grade SAE 20 motor oil. Oil FOil E+0.25% condensationproduct-phosphorus sulfide reaction product. of Example I.

Oil G-Oil E+0.5% condensation product-phos-- phorus sulfide reactionproduct of Example I1. Oil H0il E+0.5% product of Example I+0.5%

product of ExampleII.

Table I I Visi cosity 1 increase Slud ge nag/l0 g. oil

Aciditv Varnish ing. KOH/g. oil i rating z 1 4s 12 24 l 48 I 72 24 hrs.hrs. hrs. hrs. hrsv hrs.

24 hrs.

43 hrs. hm

on HT;

l Saybolt Universal viscosity at 100 F.

Table-III Oil Pour'point (ontrol (ontroi-l-0 25% condensationproduct-P285 reaction product of Example I Control+0.5% condensationproductPS,-, reaction product of Example I Control+1.0% condensationpl0dll0t--PgS5 reaction product of Example Control+0.25% neutralizedcondensation product- P285 reaction product of Example II(ontrol+0.5,--; neutralized condensation product P18 reaction product ofExample II. Control+l.0% neutralized condensation pr0duct Pass reactionproduct of Example II.

The condensation product-phosphorus sulfide reaction products, or theneutralized products thereof may be used alone as lubricating oiladditives or they may be employed in combination with other additives.For example, they may be used in combination with the reaction productof a mono-olefin polymer and a phosphorus sulfide, or the neutralizedproducts of the latter, or with the reaction product of a hydrocarbon,such as a. petroleum oil, and a phosphorus sulfide or the neutralizedproducts thereof. They may also be used along with other pour pointdepressors, sludge inhibitors, antioxidants and other additives forimparting certain desirable properties to lubricating oils.

Although I have described the use of the condensation product-phosphorussulfide reaction products in lubricating oils, which may be used in suchoils in amounts of from about 0.001% to 10.0% and preferably from about0.01% to about 3.0%, my invention is not limited to such use.

- since these products may be employed in other petroleum products suchasinsulating oils, turbine oils, greases, and the like While I havedescribed preferred embodiments of my invention, other modificationsthereof may be made without departing from the scope and spirit of theinvention, and I therefore do not wish to limit the invention to theexamples set forth herein, except insofar-as the same is .defined by thefollowing claims.

I claim:

1. A lubricant comprising a mineral lubricating oil and a small amountof the prosphorus and sulfur-containing product obtained by reacting aphosphorus sulfide with the condensation product resulting from thetreatment of a halogenated long chain parafiln with an aromatichydrocarbon in the presence of a catalyst of the Frieda- Crafts type.

2. A lubricant comprising a mineral lubricating oil and a'small amountof the phosphorus and sulfur-containing product obta ned by reacting aphosphorus sulfide with the condensation product resulting from'thetreatment of chlorinated paraffin wax with naphthalene in the presenceof aluminum chloride.

3. A lubricant as described in claim 2 in which the phosphorus sulfideis phosphorus pentasul- 4. A lubricant comprising a mineral lubricatingoil and a small amount of the phosphorus and sulfur-containing productobtained by reacting a phosphorus sulfide with the condensa tion productresulting from the treatment of a halogenated paraffin with an aromatichydrocarbon in the presenceof a catalyst of the Friedel- Crafts type andsubsequently neutralizing the reaction product of the phosphorus sulfideand the condensation product with a basic reagent containing a metalconstituent.

5. A lubricant as described in claim 4 in which the neutralized productcontains potassium.

6. A lubricant comprising a mineral lubricating oil and a small amountof the phosphorus and sulfur-containing product obtained by reacting aphosphorus pentasulfide and the condensation product resulting from thetreatment of chlorinated paraifin wax with naphthalene in the presenceof aluminum chloride and subsequently neu-' tralizing the reactionproduct of the phosphorus pentasulfide and the condensation product witha basic reagent having a metal constituent.

7. A lubricant as described in claim 6 in which the neutralized productcontains potassium.

8. A lubricant as described in claim 6 in which the neutralized productcontains sodium.

9. A lubricant as described in claim 6 in which the neutralized productcontains calcium.

10. A mineral oil composition comprising a viscous mineral oil and inadmixture therewith the phosphorus and sulfur-containing reactionproduct of a phosphorus sulfide and the condensation product obtained bytreating a halogenated long chain paraffin with an aromatic hydrocarbonin the presence of a catalyst of the Friedel-Crafts type, said reactionproduct being present in an amount suflicient to improve the viscousmineral oil with respect to lowering the pour point, inhibitingoxidation and preventing varnish formation- 11. A mineral oilcomposition as described in claim 10 in which the reaction product isneutralized.

12. A mineral oil composition as described in claim 10 in which thereaction product is neu-.

tralized with a basic potassium compound.

13. The method of inhibiting the formation of deposits of the type ofsludge, carbon and varnish in an internal combustion engine during usecomprising lubricating said engine with a lubricant comprising alubricating oil normally susceptible to form sludge, carbon and varnishin an internal combustion engine during use and a small amount of thephosphorus and sulfur-containing product obtained by reacting aphosphorus sulflde with the condensation product resulting from thetreatment of halogenated long chain paraflin with an aromatichydrocarbon in the presence of a catalyst of the Friedel-Crafts type.

14. The method of inhibiting the formation of deposits of the type ofsludge, carbon and varnish in an internal combustion engine during usecomprising lubricating said engine with a lubricant comprising alubricating oil normally susceptible to form sludge, carbon and varnishin an internal combustion engine during use and a small amount of thephosphorus and sulfur-containing product obtained by reacting aphosphorus sulfide with the condensation product resulting from thetreatment of chlorinated paraffin wax with naphthalene in the presenceof aluminum chloride.

15. The method of inhibiting the formation of deposits of the yp ofsludge, carbon and varnish in an internal combustion engine during usecomprising lubricating said engine with a lubricant comprising alubricating oilnormally susceptible to form sludge, carbon and varnishin an internal combustion engine during use and a small amount of thephosphorus and sulfur-containing product obtained by reacting aphosphorus sulfide and the condensation product resulting from thetreatment of a halogenated paraflin with an aromatic hydrocarbon in thepresence of a catalyst of the Friedel-Crafts type and subsequentlyneutralizing the reaction product of the phosphorus sulfide and thecondensation product with a basic reagent.

16. The method of inhibiting the formation of deposits of the type ofsludge, carbon and varnish in an internal combuston engine during usecomprising lubricating said engine with a lubricant comprising alubricating oil normally susceptible to form sludge, carbon and varnishin an internal combustion engine during use and a small amount of thephosphorus and sulfur containing product obtained by reacting aphosphorus pentasulfide with the condensation product resulting from thetreatment of chlorinated paraffin wax with naphthalene in the presenceof aluminum chloride and subsequently neutralizing the reaction productof the phosphorus pentasulfide and the condensation product with a basicreagent having a metal constituent.

17. The method as described in claim 16 in which the neutralized productcontains potassium.

18. A new composition of matter comprising a hydrocarbon oil and thephosphorus and sulfurcontaining product obtained by reacting aphosphorus sulfide with the condensation product resulting from thetreatment of a halogenated long chain paraifin with an aromatichydrocarbon in the presence of a catalyst of the Friedel-Crafts 19. Anew composition of matter comprising a hydrocarbon oil and thephosphorus and sulfurcontaining product obtained by reacting aphosphorus sulfide with a condensation product resulting from thetreatment of chlorinated paraflln wax with naphthalene in the presenceof aluminum chloride.

20. A new composition of matter comprising a hydrocarbon oil and theneutralized phosphorus and sulfur-containing product obtained byreacting a phosphorus sulfide with the condensation product resultingfrom the treatment of a halogenated paraflin with anaromatic hydrocarbonin the presence of a catalyst of the Friedel-Crafts type andsubsequently neutralizing the reaction product of the phosphorus sulfideand the con densation product with a basic reagent containing a metalconstituent 21. A new composition of matter as described in claim 20 inwhich the halogenated parafiin is chlorinated paraflin wax and thearomatic hydrocarbon is naphthalene.

22. A new composition of matter as described in claim 20 in which theneutralized product contains an alkali metal constituent.

23. A new composition of matter as described in claim 20 in which theneutralized product contains potassium.

24. A new composition of matter as described in claim 20 in which theneutralized product contains sodium.

25. A new composition of matter as described in claim 20 in which theneutralized product contains an alkaline earth metal constituent.

26. A new composition of matter as described in claim 20 in which theneutralized product contains calcium.

FREDERICK H. MACLAREN.

